Angular JS – 9 (End to End Testing – manual)

Continuing from the previous blog, lets look at end to end testing. Based on what you have seen so far, it is very obvious without telling, how easy it to test Angular JS. The true separation of view and controller lend itself to test controller very easily. Everything is injectable which makes everything mockable in Angular JS. Now that we know, we can test controller with ease with Jasmine and Karma. Lets look at the other cool testing we can do in Angular, which is End To End test.

Angular End to End test allows the developer to do UI testing. This allows developer to enter values directly in the DOM elements and perform operations and then validate the results. This have been a difficult task so far with other client technologies and Angular JS made it easy for us. These end to end tests are called scenario tests. Angular follows Jasmine model of writing tests for end to end test as well.

If you have not already downloaded the Intro to Karma from Github, please download and we will use the same code to go over the end to end test.

There are two ways one could run end to end test. The first approach is to create your test and run the test manually and verify if the tests are passing. The second approach is to have the test run automatically in the background all the time while you developing your application and writing the tests. With this approach there is no need to run the test every time one would make a change to the code or tests. We will review the first approach in this blog.

Manual Test:

First lets look at the test we are going to write. Our application is very simple, it takes two numbers, multiplies and show the result on the screen as shown below

The two input fields are bound to ‘firstNumber’ and ‘secondNumber’, so in our test, we need to enter values for those two fields. Then find the button and click the button. Which would then perform the multiplication and save the result to ‘result’. So to confirm our UI code worked properly, we need to verify if ‘result’ contains the expected result. With this knowledge lets look at the test. The end to end test is available under test\e2e\mainscenario.js

As I mentioned before, end to end test also borrowed testing pattern from jasmine where we describe what we are testing and before each test and after each test, one could perform some task. All tests where marked by ‘it’. So going back to the test we were going to do;

Line 1: starts the test with ‘it’, followed by two parameters, first one is the description of the test, followed by the test itself.

Line 2: Find the input for ‘firstNumber’ and enter value ‘2’.

Line 3: Find the input for ‘secondNumber’ and enter value ‘2’.

Line 4: Find the only button and click the button to perform multiplication.

Line 5: Find the ‘result’ and verify the result is ‘4.00’. Even though when we multiply 2 * 2 is 4, by default the decimal digit is set to 2 and result ‘4’ is send to number filter so the result becomes ‘4.00’.

When we do end to end test, we are testing the html page, so before each test, we need to make sure, the browser is pointing to the page under test. To do that, one need to define the beforeEach or at the start of each test. In our case, we define a beforeEach to route to the index.html as shown below

Line 2: has ‘../../app/index.html’. This is very important. To run, end to end test, one need to run the a web server first. Since I will be using node and the web server script is at test/script, it is very important you run the web server first from this location as follows

node test\scripts\web-server.js

now if you follow the line (2), what we are doing is, trying to find index.html from app folder two directories up from web-server.js location. That’s why we have the navigation. If web-server.js placed in root directory, then our navigateto would be ‘app/index.html’.

With node server is running, we need to create a html file to run our end to end script. It will be very simple script, we need to point to angular-scenario.js script and also our end to end script that’s all about it. So here is our runner.html file

1<!doctype html> 2<!-- to run e2e make sure you are running your web server --> 3<!-- in our example we run node test/scripts/web-server .js --> 4<!-- also open browser and point to http://localhost:8000/test/runner.html --> 5<!-- we need to make sure we run node same way when we run the e2e test in command line as well --> 6<html lang="en"> 7<head> 8<title>End2end Test Runner</title> 9<script src="lib/angular-scenario.js" ng-autotest></script>10<script src="e2e/mainscenario.js"></script>11</head>12<body>13</body>14</html>

Please read step 2-5 in the html file to make sure everything is setup.

Now launch Chrome and point to the url in line 4 and that is it. You will have your end to end test run.